Packaging and interconnection of contact structure

ABSTRACT

A packaging and interconnection for connecting a contact structure to an outer peripheral component. The packaging and interconnection includes a contact structure made of conductive material and formed on a contact substrate, a contact trace formed on the contact substrate and connected to the contact structure, a contact pad formed on a bottom surface of the contact substrate and connected to the contact structure through a via hole and the contact trace, a contact target provided at an outer periphery of the contact structure to be electrically connected with the contact pad, and a conductive member for connecting the contact pad and the contact target.

This is a continuation of U.S. patent application No. 09/282,506 filedMar. 31, 1999.

FIELD OF THE INVENTION

This invention relates to an electronic packaging and interconnection ofa contact structure, and more particularly, to an electronic packagingand interconnection for mounting a contact structure on a probe card orequivalent thereof which is used to test semiconductor wafers,semiconductor chips, packaged semiconductor devices or printed circuitboards and the like with increased accuracy, density and speed.

BACKGROUND OF THE INVENTION

In testing high density and high speed electrical devices such as LSIand VLSI circuits, high performance probe contactors or test contactorsmust be used. The electronic packaging and interconnection of a contactstructure of the present invention is directed to the application oftesting and burn-in testing of semiconductor wafers and dies, but notlimited to such applications and is inclusive of testing and burn-intest of packaged semiconductor devices, printed circuit boards and thelike. However, for the convenience of explanation, the present inventionis described in the following mainly with reference to a probe card tobe used in semiconductor wafer testing.

In the case where semiconductor devices to be tested are in the form ofa semiconductor wafer, a semiconductor test system such as an IC testeris usually connected to a substrate handler, such as an automatic waferprober, to automatically test the semiconductor wafer. Such an exampleis shown in FIG. 1 in which a semiconductor test system has a test head100 which is ordinarily in a separate housing and electrically connectedto the test system through a bundle of cables. The test head 100 and thesubstrate handler 400 are mechanically connected with one another bymeans of a manipulator 500 and a drive motor 510. The semiconductorwafers to be tested are automatically provided to a test position of thetest head by the substrate handler such as a wafer prober.

On the test head, the semiconductor wafer to be tested is provided withtest signals generated by the semiconductor test system. The resultantoutput signals from the semiconductor wafer under test are transmittedto the semiconductor test system wherein they are compared with expecteddata to determine whether IC circuits (chips) on the semiconductor waferfunction correctly or not.

As shown in FIGS. 1 and 2, a test head 100 and a substrate handler 400are connected with each other through an interface component 140. Theinterface component 140 includes a performance board 120 which istypically a printed circuit board having electric circuit connectionsunique to a test head's electrical footprint, such as coaxial cables,pogo-pins and connectors. The test head 100 includes a large number ofprinted circuit boards 150 which correspond to the number of testchannels (tester pins) of the semiconductor test system. Each of theprinted circuit boards 150 has a connector 160 to receive therein acorresponding contact terminal 121 of the performance board 120.

In the example of FIG. 2, a “frog” ring 130 is mounted on theperformance board 120 to accurately determine the contact positionsrelative to the substrate handler 400 such as a wafer prober. The frogring 130 has a large number of contact pins 141 formed, for example, byZIF connectors or pogo-pins, connected to the contact terminals 121,through coaxial cables 124.

FIG. 2 further shows a structural relationship between the substratehandler 400, the test head 100 and the interface component 140 whentesting a semiconductor wafer. As shown in FIG. 2, the test head 100 isplaced over the substrate handler 400 and mechanically and electricallyconnected to the substrate handler through the interface component 140.In the substrate handler 400, a semiconductor wafer 300 to be tested ismounted on a chuck 180. A probe card 170 is provided above thesemiconductor wafer 300 to be tested. The probe card 170 has a largenumber of probe contactors (contact structures) 190, such as cantileversor needles, to contact with circuit terminals or contact targets orcontact pads in the IC circuit of the semiconductor wafer 300 undertest.

Electrical terminals or contact receptacles of the probe card 170 areelectrically connected to the contact pins 141 provided on the frog ring130. The contact pins 141 are also connected to the contact terminals121 of the performance board 120 via the coaxial cables 124 where eachcontact terminal 121 is connected to the printed circuit board 150 ofthe test head 100. Further, the printed circuit boards 150 are connectedto the semiconductor test system main frame through the cable bundle 110having several hundreds of cables therein.

Under this arrangement, the probe contactors (needles or cantilevers)190 contact the surface of the semiconductor wafer 300 on the chuck 180to apply test signals to the IC chips on the semiconductor wafer 300 andreceive the resultant signals of the IC chips from the wafer 300. Theresultant output signals from the semiconductor wafer 300 under test arecompared with the expected data generated by the semiconductor testsystem to determine whether the IC chips in the semiconductor wafer 300properly perform the intended functions.

FIG. 3 is a bottom view of the probe card 170 of FIG. 2. In thisexample, the probe card 170 has an epoxy ring on which a plurality ofprobe contactors 190 called needles or cantilevers are mounted. When thechuck 180 mounting the semiconductor wafer 300 moves upward in FIG. 2,the tips of the cantilevers 190 contact the contact targets such ascontact pads or bumps on the wafer 300. The ends of the cantilevers 190are connected to wires 194 which are further connected to transmissionlines (not shown) formed in the probe card 170. The transmission linesin the probe card 170 are connected to a plurality of electrodes 197which further contact the pogo pins 141 of FIG. 2.

Typically, the probe card 170 is structured by a multilayer of polyimidesubstrates having ground planes, power planes, signal transmission linesin many layers. As is well known in the art, each of the signaltransmission lines is designed to have a characteristic impedance suchas 50 ohms by balancing the distributed parameters, i.e., dielectricconstant and magnetic permeability of the polyimide, inductances andcapacitances of the signal paths within the probe card 170. Thus, thesignal transmission lines are impedance matched to achieve a highfrequency transmission bandwidth to the wafer 300 under test. The signaltransmission lines transmit a small current during a steady state of apulse signal and a large peak current during a transition state of thedevice's outputs switching. For removing noise, capacitors 193 and 195are provided on the probe card 170 between the power and ground planes.

An equivalent circuit of the probe card 170 is shown in FIGS. 4A-4E toexplain the limitations of bandwidth in the conventional probe cardtechnology. As shown in FIGS. 4A and 4B, the signal transmission line onthe probe card 170 extends from the electrode 197, the strip line(impedance matched line) 196, the wire 194 and to the needle(cantilever) 190. Since the wire 194 and needle 190 are not impedancematched, these portions function as an inductor L in the high frequencyband as shown in FIG. 4C. Because of the overall length of the wire 194and needle 190 is around 20-30 mm, the value of the inductor L is nottrivial, resulting in the significant frequency limitation in testing ahigh frequency performance of a device under test.

Other factors which limit the frequency bandwidth in the probe card 170reside in both power and ground needles shown in FIGS. 4D and 4E. If apower line can provide large enough currents to the device under test,it will not seriously limit the operational bandwidth in testing thedevice. However, because the series connected wire 194 and needle 190for supplying the power to the device under test are equivalent to theinductors as shown in FIG. 4D, which impede the high speed current flowin the power line. Similarly, because the series connected wire 194 andneedle 190 for grounding the power and signals are equivalent to theinductors as shown in FIG. 4E, the high speed current flow is impeded bythe wire 194 and needle 190.

Moreover, the capacitors 193 and 195 are provided between the power lineand the ground line to secure a proper performance of the device undertest by filtering out the noise or surge pulses on the power lines. Thecapacitors 193 have a relatively large value such as 10 μF and can bedisconnected from the power lines by switches if necessary. Thecapacitors 195 have a relatively small capacitance value such as 0.01 μFand fixedly connected close to the DUT (device under test). Since thesecapacitors serve as high frequency decoupling on the power lines, whichalso impede the high speed current flow in the signal and power lines.

Accordingly, the probe contactors noted above are limited to thefrequency bandwidth of approximately 200 MHz which is insufficient totest recent semiconductor devices. It is considered, in the industry,that the frequency bandwidth equal to the tester's capability, which iscurrently on the order of 1 GHz or higher, will be necessary in the nearfuture. Further, it is desired in the industry that a probe card iscapable of handling a large number of semiconductor devices, especiallymemory devices, such as 32 or more, in a parallel fashion at the sametime to increase test throughput.

To meet the next generation test requirements noted above, the inventorsof this application has provided a new concept of contact structure inthe U.S. application Ser. No. 09/099,614 “Probe Contactor Formed byPhotolithography Process” filed Jun. 19, 1998. The contact structure isformed on a silicon or dielectric substrate through a photolithographyprocess. FIGS. 5 and 6A-6C show the contact structure in the above notedapplication. In FIG. 5, all of the contact structures 30 are formed on asilicon substrate 20 through the same photolithography process. Thesilicon substrate 20 having the contact structures 30 may be mounted ona probe card such as shown in FIGS. 2 and 3. When the semiconductorwafer 300 under test moves upward, the contact structures 30 contactwith corresponding contact targets (electrodes or pads) 320 on the wafer300.

The contact structure 30 on the silicon substrate 20 can be directlymounted on a probe card such as shown in FIG. 3, or molded in a package,such as a traditional IC package having leads, so that the package ismounted on a probe card. In the above noted patent application by theinventors, such technologies of packaging and interconnection of thecontact structure 30 with respect to the probe card or equivalentthereof is not described.

SUMMARY OF THE INVENTION

Therefore, it is an object of the present invention to provide apackaging and interconnection of a contact structure with respect to aprobe card or equivalent thereof to be used in testing a semiconductorwafer, packaged LSI and the like.

It is another object of the present invention to provide a packaging andinterconnection of a contact structure with respect to a probe card orequivalent thereof to achieve a high speed and high frequency operationin testing a semiconductor wafer, packaged LSI and the like.

It is a further object of the present invention to provide a packagingand interconnection of a contact structure with respect to a probe cardor equivalent thereof wherein the packaging and interconnection isformed at a bottom surface of the substrate mounting the contactstructure.

It is a further object of the present invention to provide a packagingand interconnection of a contact structure which is established througha bonding wire, a single layer tape automated bonding (TAB), or amulti-layer tape automated bonding (TAB) at the bottom surface of thesubstrate mounting the contact structure.

It is a further object of the present invention to provide a packagingand interconnection of a contact structure which is established betweena contact pad formed at the bottom surface of the substrate mounting thecontact structure and an electric connector.

It is a further object of the present invention to provide a packagingand interconnection of a contact structure which is established betweena contact pad formed at the bottom surface of the substrate mounting thecontact structure and an interconnect pad of a printed circuit boardthrough a solder bump.

It is a further object of the present invention to provide a packagingand interconnection of a contact structure which is established betweena contact pad formed at the bottom surface of the substrate mounting thecontact structure and an interconnect pad of a printed circuit boardthrough a conductive polymer.

In the present invention, an electronic packaging and interconnection ofa contact structure to be used in a probe card or equivalent thereof totest semiconductor wafers, semiconductor chips, packaged semiconductordevices or printed circuit boards and the like is established between acontact pad formed at the bottom surface of the substrate mounting thecontact structure and various types of connection means on the probecard. The contact pad at the bottom is connected to the contactstructure at an upper surface of the substrate through a via hole and acontact trace both of which are provided on the substrate.

In one aspect of the present invention, a packaging and interconnectionof a contact structure is comprised of: a contact structure made ofconductive material and formed on a contact substrate through aphotolithography process wherein the contact structure has a baseportion vertically formed on the contact substrate, a horizontalportion, one end of which being formed on the base portion, and acontact portion vertically formed on another end of the horizontalportion; a contact pad formed on a bottom surface of the contactsubstrate and electrically connected to the contact structure through avia hole and a contact trace; a contact target provided on a printedcircuit board (PCB) substrate to be electrically connected with thecontact pad on the contact substrate through a conductive bump orpolymer.

In another aspect of the present invention, a packaging andinterconnection of a contact structure is comprised of: a contactstructure made of conductive material and formed on a contact substratethrough a photolithography process wherein the contact structure has abase portion vertically formed on the contact substrate, a horizontalportion, one end of which being formed on the base portion, and acontact portion vertically formed on another end of the horizontalportion; a contact pad formed on a bottom surface of the contactsubstrate and electrically connected to the contact structure through avia hole and a contact trace; a contact target provided on a printedcircuit board (PCB) substrate or lead frame to be electrically connectedwith the contact pad on the contact substrate through a bonding wire;and a support structure for supporting the contact structure and thecontact substrate.

In a further aspect of the present invention, a packaging andinterconnection of a contact structure is comprised of: a contactstructure made of conductive material and formed on a contact substratethrough a photolithography process wherein the contact structure has abase portion vertically formed on the contact substrate, a horizontalportion, one end of which being formed on the base portion, and acontact portion vertically formed on another end of the horizontalportion; a contact pad formed on a bottom surface of the contactsubstrate and electrically connected to the contact structure through avia hole and a contact trace; a contact target provided on a printedcircuit board (PCB) substrate or lead frame to be electrically connectedwith the contact pad on the contact substrate through a tape automatedbonding (TAB) lead; an elastomer provided under the contact substratefor allowing flexibility in the interconnection and packaging; and asupport structure for supporting the contact structure, the contactsubstrate and the elastomer.

In a further aspect of the present invention, a connector is provided toreceive the TAB lead connected to the contact pad to establishelectrical connection therebetween. In a further aspect of the presentinvention, a conductive bump is provided between the TAB lead connectedto the contact pad and the PCB pad to establish electrical connectionthereamong. In a further aspect of the present invention, a conductivepolymer is provided between the TAB lead connected to the contact padand the PCB pad to establish electrical connection thereamong.

In a further aspect of the present invention, the interconnection andpackaging of the contact structure is established through a bonding wirebetween the contact pad on the contact substrate and a contact target.In a further aspect of the present invention, the interconnection andpackaging of the contact structure is established through a single layerTAB lead extending between the contact pad on the contact substrate anda contact target. In a further aspect of the present invention, theinterconnection and packaging of the contact structure is establishedthrough a double layer TAB lead extending between the contact pad on thecontact substrate and a contact target. In a further aspect of thepresent invention, the interconnection and packaging of the contactstructure is established through a triple layer TAB lead extendingbetween the contact pad on the contact substrate and a contact target.

According to the present invention, the packaging and interconnectionhas a very high frequency bandwidth to meet the test requirements in thenext generation semiconductor test technology. The packaging andinterconnection is able to mount the contact structure on a probe cardor equivalent thereof by electrically connecting therewith through thebottom surface of the contact substrate mounting the contact structure.Moreover, because of the relatively small number of overall componentsto be assembled, the interconnection and packaging of the presentinvention can be fabricated with low cost and high reliability as wellas high productivity.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram showing a structural relationship betweena substrate handler and a semiconductor test system having a test head.

FIG. 2 is a schematic diagram showing an example of detailed structurefor connecting the test head of the semiconductor test system to thesubstrate handler.

FIG. 3 is a bottom view showing an example of the probe card having anepoxy ring for mounting a plurality of cantilevers as probe contactors.

FIGS. 4A-4E are circuit diagrams showing equivalent circuits of theprobe card of FIG. 3.

FIG. 5 is a schematic diagram showing contact structures associated withthe present invention produced through a photolithography process.

FIGS. 6A-6C are schematic diagrams showing examples of contact structureassociated with the present invention formed on a silicon substrate.

FIG. 7 is a schematic diagram showing a first embodiment of the presentinvention in which the packaging and interconnection is establishedbetween a contact pad provided at a bottom surface of the contactsubstrate mounting the contact structure and a PCB (printed circuitboard) pad by a conductive bump.

FIG. 8 is a schematic diagram showing a modified structure of the firstembodiment of the present invention wherein a conductive polymer is usedbetween the contact pad and the PCB pad.

FIG. 9 is a schematic diagram showing a second embodiment of the presentinvention in which the packaging and interconnection is established by abonding wire between a contact pad provided at a bottom surface of thecontact substrate mounting the contact structure and a contact targetprovided on a probe card or a device package.

FIG. 10 is a schematic diagram showing a modified structure of thesecond embodiment of the present invention wherein the contact target isa PCB pad.

FIG. 11 is a schematic diagram showing a third embodiment of the presentinvention in which the packaging and interconnection is established by asingle layer TAB (tape automated bonding) lead between a contact padprovided at a bottom surface of the contact substrate mounting thecontact structure and a contact target on a probe card or a devicepackage.

FIG. 12 is a schematic diagram showing a modified structure of the thirdembodiment of the present invention in which a straight shape TAB leadis incorporated as an interconnection and packaging member.

FIG. 13 is a schematic diagram showing a further modified structure ofthe third embodiment of the present invention in which a contact targetis a connector.

FIG. 14 is a schematic diagram showing a further modified structure ofthe third embodiment of the present invention in which a conductive bumpis incorporated between the TAB lead and the contact target as one ofinterconnection and packaging members.

FIG. 15 is a schematic diagram showing a further modified structure ofthe third embodiment of the present invention in which a conductivepolymer is incorporated between the TAB lead and the contact target asone of interconnection and packaging members.

FIG. 16 is a schematic diagram showing a fourth embodiment of thepresent invention in which the packaging and interconnection isestablished by a double layer TAB (tape automated bonding) lead betweena contact pad provided at a bottom surface of the contact substratemounting the contact structure and a contact target on a probe card or adevice package.

FIG. 17 is a schematic diagram showing a modified structure of thefourth embodiment of the present invention in which a straight shapedouble layer TAB lead is incorporated as an interconnection andpackaging member to be connected to a pair of contact targets.

FIG. 18 is a schematic diagram showing a further modified structure ofthe fourth embodiment of the present invention in which a contact targetis a connector to be connected with the double layer TAB lead.

FIG. 19 is a schematic diagram showing a further modified structure ofthe fourth embodiment of the present invention in which a contact targetis a connector to be connected with the straight shape double layer TABlead.

FIG. 20 is a schematic diagram showing a further modified structure ofthe fourth embodiment of the present invention in which a conductivebump is incorporated between the TAB lead and the contact target as oneof interconnection and packaging members.

FIG. 21 is a schematic diagram showing a further modified structure ofthe fourth embodiment of the present invention in which a pair ofconductive bumps are incorporated between the double layer TAB lead andthe contact targets as interconnection and packaging members.

FIG. 22 is a schematic diagram showing a further modified structure ofthe fourth embodiment of the present invention in which a conductivepolymer is incorporated between the double layer TAB lead and thecontact target as one of interconnection and packaging members.

FIG. 23 is a schematic diagram showing a further modified structure ofthe fourth embodiment of the present invention in which a pair ofconductive polymer are incorporated between the double layer TAB leadand the contact targets as interconnection and packaging members.

FIG. 24 is a schematic diagram showing a fifth embodiment of the presentinvention in which the packaging and interconnection is established by atriple layer TAB (tape automated bonding) lead between a contact padprovided at a bottom surface of the contact substrate mounting thecontact structure and a contact target on a probe card or a devicepackage.

FIG. 25 is a schematic diagram showing a modified structure of the fifthembodiment of the present invention in which a straight shape triplelayer TAB lead is incorporated as one of interconnection and packagingmembers to be connected to three contact targets.

FIG. 26 is a schematic diagram showing a further modified structure ofthe fifth embodiment of the present invention in which a contact targetis a connector to be connected with the triple layer TAB lead.

FIG. 27 is a schematic diagram showing a further modified structure ofthe fifth embodiment of the present invention in which a contact targetis a connector to be connected with the straight shape triple layer TABlead.

FIG. 28 is a schematic diagram showing a further modified structure ofthe fifth embodiment of the present invention in which a conductive bumpis incorporated between the TAB lead and the contact target as one ofinterconnection and packaging members.

FIG. 29 is a schematic diagram showing a further modified structure ofthe fifth embodiment of the present invention in which three conductivebumps are incorporated between the triple layer TAB lead and the contacttargets as interconnection and packaging members.

FIG. 30 is a schematic diagram showing a further modified structure ofthe fifth embodiment of the present invention in which a conductivepolymer is incorporated between the triple layer TAB lead and thecontact target as one of interconnection and packaging members.

FIG. 31 is a schematic diagram showing a further modified structure ofthe fifth embodiment of the present invention in which three conductivepolymer are incorporated between the triple layer TAB lead and thecontact targets as interconnection and packaging members.

FIG. 32 is a schematic diagram showing a sixth embodiment of the presentinvention in which the packaging and interconnection is established by asingle layer TAB (tape automated bonding) lead between a contact traceprovided at an upper surface of the contact substrate and a firstcontact target as well as a double layer TAB lead between a contact padprovided at a bottom surface of the contact substrate and a secondcontact target.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

To establish a packaging and interconnection of a contact structuredirectly with a probe card or indirectly with a probe card through an ICpackage, examples of FIGS. 6A-6C show basic three types of electricalpath extended from the contact structure to form such interconnections.FIG. 6A shows an example in which such an electrical connection isestablished at the top of the substrate. FIG. 6B shows an example inwhich an electrical connection is established at the bottom of thesubstrate while FIG. 6C shows an example in which an electricalconnection is formed at the edge of the substrate. Almost any types ofexisting IC package design or probe card design can accommodate at leastone of the interconnect types of FIGS. 6A-6C.

Each of FIGS. 6A-6C include a contact interconnect trace 32 alsodesignated by a which is to establish electrical connection with a probecard or any intermediate member to a probe card. The contact structure30 has vertical portions b and d and a horizontal beam c and a tipportion e. The tip portion e of the contact structure 30 is preferablysharpened to achieve a scrubbing effect when pressed against contacttargets 320 such as shown in FIG. 3. The spring force of the horizontalbeam c provides an appropriate contact force against the contact target320. An example of material of the contact structure 30 and the contacttrace 32 includes nickel, aluminum, copper and other conductivematerials. The inventors of this application have provided a detaileddescription of production process of the contact structure 30 and thecontact interconnect trace 32 on the silicon substrate 20 in the abovenoted U.S. application Ser. No. 09/099,614.

In the present invention, the packaging and interconnection of a contactstructure is directed to the type of structure having a contact pad 36provided at a bottom surface of the substrate 20, i.e., the bottom typecontact pad as shown in FIG. 6B. The contact pad 36 is connected to thecontact structure 30 through a via hole 35 and the contact trace 32. Thecontact structure 30 is formed on the top surface of the contactsubstrate 20. Various embodiments of the present invention on the bottomtype packaging and interconnection will be described with reference tothe drawings.

FIG. 7 is a schematic diagram showing a first embodiment of the presentinvention in which the packaging and interconnection is establishedbetween the contact pad provided at the bottom surface of the contactsubstrate mounting the contact structure and a connection target such asa PCB (printed circuit board) pad through a conductive bump or aconductive polymer.

In the first example of FIG. 7, a contact structure 30 formed on acontact substrate 20 is electrically connected to a contact pad 36provided at the bottom surface of the contact substrate 20 through acontact trace 32 and a via hole 35. The contact structure 30 is formedon the top surface of the contact substrate 20. The contact pad 36 atthe bottom of the contact substrate 20 is positioned over a printcircuit board (PCB) interconnect pad 38 on a printed circuit board (PCB)62. A conductive bump 56 electrically connects the contact pad and thePCB pad. The contact substrate 20 is a silicon substrate although othertypes of dielectric substrate, such as glass epoxy, polyimide, ceramic,and alumina substrates are also feasible.

Typically, the conductive bump 56 is a solder bump used in a standardsolder ball technology. By the application of the heat, the conductivebump 56 is reflowed onto the PCB pad 38 for attachment between thecontact pad 36 and the PCB pad 38. Another example of the conductivebump 56 is a fluxless solder ball used in a plasma-assisted drysoldering technology. Further examples of conductive bump will be givenlater with respect to further embodiments of the present invention.

In the example of FIG. 8, a conductive polymer 66 is used between thecontact pad 36 provided at the bottom surface of the contact substrate20 and the PCB pad 38 (connection target) on the PCB substrate 62. Thecontact substrate 20 is a silicon substrate although other types ofdielectric substrate, such as glass epoxy, polyimide, ceramic, andalumina substrates are also feasible. An example of the conductivepolymer 66 is a conductive elastomer which is filled with conductivewire that extends beyond the surface of the elastomer. Most conductivepolymers are designed to be conductive between the mating electrodesnormally in vertical or angled directions and not conductive in thehorizontal direction. Further examples of conductive polymer will begiven later with respect to further embodiments of the presentinvention.

FIGS. 9 and 10 show a second embodiment of the present invention whereinthe bottom type contact pad is coupled to a connection target such as alead frame or a printed circuit board provided, for example, on a probecard (not shown) or an IC package (not shown) through a bonding wire. Inthe first example of FIG. 9, a contact structure 30 formed on a contactsubstrate 20 is electrically connected to a contact pad 36 provided atthe bottom surface of the contact substrate 20 via a contact trace 32and a through hole 35. The contact structure 30 is formed on the topsurface of the contact substrate 20. The contact pad 36 is designed toestablish an electrical connection with contact or connection targetssuch as a lead frame 45 through various contact means such as a bondingwire 72. The bonding wire 72 is a thin wire of 15-25 μm diameter andmade, for example, of gold or aluminum.

Typically, the contact substrate 20 is a silicon substrate althoughother types of dielectric substrate, such as glass epoxy, polyimide,ceramic, and alumina substrates are also feasible. In the example ofFIG. 9, the bonding wire 72 connects the contact pad 36 and the leadframe 45 of, for example, a probe card. The contact substrate 20 and thelead frame 45 are mounted on a support structure 52 through, forexample, an adhesive (not shown).

Any wire bonding procedure can be used to establish the connectionbetween the contact pad 36 and the contact target. The bonding wire 72is first bonded to the contact pad 36 of the contact substrate andspanned to the lead frame 45. The wire 72 is bonded to the lead frame 45and is clipped, and the entire process above is repeated at the nextbonding location. The wire bonding is done with either gold or aluminumwires. Both materials are highly conductive and ductile enough towithstand deformation during the bonding steps and still remainingstrong and reliable. In the gold wire bonding, thermo-compression (TC)and thermosonic methods are typically used. In the aluminum wirebonding, ultrasonic and wedge bonding methods are typically used.

In the example of FIG. 10, the contact pad 36 at the bottom of thecontact substrate is connected to a printed circuit board (PCB)interconnect pad 38 provided on a PCB substrate 62 ₂ through a bondingwire 72. The PCB substrate 62 ₂ can be a probe card such as shown inFIG. 3 or an intermediate circuit component provided between the contactstructure and the probe card. The PCB substrate is mounted on a supportstructure 52. The contact substrate 20 and the support structure 52 arefixed with one another by, for example, an adhesive (not shown).Similarly, the PCB substrate 62 ₂ and the support structure 52 are fixedwith one another by an adhesive (not shown)

FIGS. 11-15 show a third embodiment of the present invention wherein thebottom type contact pad is coupled to a contact target through a singlelayer lead formed by a tape automated bonding (TAB) process. In thefirst example of FIG. 11, the contact structure 30 formed on a topsurface of the contact substrate 20 is electrically connected to thecontact pad 36 at the bottom of the substrate 20 via the contact trace32 and the through hole 35. The contact pad 36 is connected at itsbottom surface with a single layer TAB lead 74 whose other end is alsoconnected to a connection target such as a printed circuit board (PCB)interconnect pad 38 provided on a PCB substrate 62.

The contact substrate 20 is mounted on the PCB substrate 62 through anelastomer 42 and a support structure 52 ₂. The contact substrate 20, theelastomer 42, the support structure 52 ₂ and the PCB substrate 62 arefixed with one another by, for example, an adhesive (not shown). In thisexample, the TAB lead 74 for connecting the contact pad 36 and the PCBpad 38 has a gull-wing shape where a gull-wing (lower) portion is bondedto the PCB pad 38. A support member 54 is provided on the supportstructure 52 ₂ to support the TAB lead 74.

As noted above, the TAB lead 74 has a gull-wing shape which is similarto the standard “gull-wing lead” used in a surface mount technology.Because of the down-ward bent of the gull-wing type TAB lead 74, asufficient vertical clearance is achieved at the left side of FIG. 11over the contact portion between the PCB pad 38 and the TAB lead 74. Thelead form of the TAB lead 74 (downward bent, gull-wing lead) may requirespecial tooling to produce the same. A large number of interconnectionbetween the contact pads and the PCB pads will be used in an actualapplication such as semiconductor device testing, for example severalhundred connections. Thus, such tooling may be standardized for amultiple of contact pads with given pitch.

The electrical connections between the contact pad 36 and the TAB lead74 and between the TAB lead 74 and the PCB pad 38 will be established byvarious bonding technologies including thermosonic bonding,thermocompression bonding, and ultrasonic bonding technique. In anotheraspect, such electrical connections will be established through asurface mount technology (SMT) such as using a screen printable solderpaste. A soldering process is carried out based on the reflowcharacteristics of the solder paste and other solder materials wellknown in the art.

The PCB substrate 62 itself may be a probe card such as shown in FIG. 3or provided separately from the probe card, and mounted directly orindirectly on the probe card. In the former case, the PCB 62 may makedirect contact with an interface of a semiconductor test system such asan IC tester in a manner shown in FIG. 2. In the latter case, the PCBsubstrate 62 is pinned or in use of a conductive polymer forestablishing an electrical contact to the next level of a contactmechanism on the probe card. Such types of electrical connection betweenthe PCB substrate 62 and the probe card through pins or conductivepolymer would allow for field repairability.

The PCB substrate 62 may be a multiple layer structure which is capableof providing high bandwidth signals, distributed high frequencycapacitance and integrated high frequency chip capacitors for powersupply decoupling as well as high pin counts (number of I/O pins andassociated signal paths). An example of material of the PCB 62 isstandard high performance glass epoxy resin. Another example ofmultilayer PCB substrate material is ceramic. The ceramic substrate isexpected to minimize mismatch in coefficient of temperature expansion(CTE) rates during high temperature applications such as a burn-in testof semiconductor wafers and packaged IC devices.

The support structure 52 ₂ is to establish a physical strength of thepackaging and interconnection of the contact structure. The supportstructure 52 ₂ is made of, for example, ceramic, molded plastic ormetal. The elastomer 42 is to establish flexibility in the packaging andinterconnection of the present invention to overcome a potentialplanarization mechanism. The elastomer 42 also functions to absorb amismatch in temperature expansion rates between the contact substrate 20and the PCB substrate 62.

An example of overall length of the signal path from the contactstructure 30, the contact trace 32, the contact pad 36 and the TAB lead74 is in the range of several hundred micrometers. Because of the shortpath length, the packaging interconnection of the present invention canbe easily operable in a high frequency band such as several GHz or evenhigher. Moreover, because of a relatively small number of overallcomponents to be assembled, the packaging and interconnection of thepresent invention can be fabricated with low cost and high reliabilityas well as high productivity.

FIG. 12 shows another example of the third embodiment of the presentinvention. A TAB lead 74 ₂ is straight and connects the contact pad 36at the bottom of the contact substrate 20 to the PCB pad 38 provided ona printed circuit board (PCB) substrate 62 ₃. To match the verticalposition of the PCB pad 38, the PCB substrate 62 ₃ has a raised portionat the left end thereof.

The electrical connection between the TAB lead 74 ₂ and the PCB pad 38will be established by a surface mount technology (SMT) such as using ascreen printable solder paste as well as various other bondingtechnologies including thermosonic bonding, thermocompression bonding,and ultrasonic bonding technique. Because of the significantly smallsizes of the components and signal path lengths involved in the contactstructure 30, contact trace 32, contact pad 36, and the TAB lead 74 ₂,the example of FIG. 12 can operate at a very high frequency band, suchas several GHz. Moreover, because of the small number of componentsinvolved and simple structure of the components to be assembled, theinterconnection and packaging of the present invention can be fabricatedwith low cost and high reliability as well as high productivity.

FIG. 13 shows a further modification of the third embodiment of thepresent invention wherein the bottom type contact pad 36 is coupled to aconnector provided on a printed circuit board or other structure. In theexample of FIG. 13, the contact pad 36 provided at the bottom surface ofthe contact substrate is connected to a connector 46 via a single layerTAB lead 74 ₂. The connector 46 is provided on a support structure 52₄.The contact substrate 20 is a silicon substrate although other typesof dielectric substrate, such as glass epoxy, polyimide, ceramic, andalumina substrates are also feasible.

The TAB lead 74 ₂ has a straight shape as in the example of FIG. 12. Atabout the center of FIG. 13, the contact substrate 20 is mounted on thesupport structure 52 ₄ through an elastomer 42. The contact substrate20, the elastomer 42 and the support structure 52 ₄ are attached withone another by, for example, an adhesive (not shown). The connector 46may be mechanically fixed to the support structure 52 ₄ through anattachment mechanism (not shown) . The end of the TAB lead 74 ₂ isinserted in a receptacle (not shown) of the connector 46. As is wellknown in the art, such a receptacle has a spring mechanism to provide asufficient contact force when receiving the end of the TAB lead 74 ₂therein. Between the TAB lead 74 ₂ and the support structure 52 ₄, thereis provided a support member 54 to support the TAB lead 74 ₂ extendingbetween the contact pad 36 and the connector 46. Also well known in theart, an inner surface of such a receptacle is provided with conductivemetal such as gold, silver, palladium or nickel.

The connector 46 may be integrated with straight or right angle pins,which may be connected to the receptacle noted above, for directconnection to a printed circuit board (PCB). A PCB to mount theconnector 46 thereon can be either solid or flexible. As is known in theart, a flexible PCB is formed on a flexible base material and has flatcables therein. Alternatively, the connector 46 may be integrated with acoaxial cable assembly in which a receptacle is attached to an innerconductor of the coaxial cable for receiving the end of the TAB lead 74₂ therein. The connection between the connector 46 and the TAB lead 74 ₂or the support structure 52 ₄ is not a permanent attachment method,allowing for field replacement and repairability of the contact portion.

Typically, the contact substrate 20 is a silicon substrate althoughother types of substrate, such as glass epoxy, polyimide, ceramic, andalumina substrates are also feasible. The support structure 52 ₄ is toestablish a physical strength of the packaging and interconnection ofthe contact structure. The support structure 52 ₄ is made of, forexample, ceramic, molded plastic or metal. The elastomer 42 is toestablish flexibility in the interconnection and packaging of thepresent invention to overcome a potential planarization mechanism. Theelastomer 42 also functions to absorb a mismatch in temperatureexpansion rates between the contact substrate 20 and a PCB substrate tomount the connector 46 thereon.

An example of an overall signal path length from the contact structure30, the contact trace 32, the contact pad 36 to the end of the TAB lead74 ₂ is in the range of several hundred micrometers. Because of theshort path length, the interconnection and packaging of the presentinvention can be easily operable in a high frequency band such asseveral GHz or even higher. Moreover, because of the lower total numberof components to be assembled, the packaging and interconnection of thepresent invention can be fabricated with low cost and high reliabilityas well as high productivity.

FIG. 14 shows a further example of the third embodiment of the presentinvention wherein the bottom type contact pad is coupled to a connectiontarget such as an interconnect pad provided on a printed circuit boardthrough a conductive bump. In the example of FIG. 14, a contactstructure 30, a contact trace 32, a via hole 35, and a contact pad 36are formed on a contact substrate 20. The contact structure 30 is formedon the upper surface of the contact substrate 20 while the contact pad36 is formed on the bottom surface of the substrate 20. Typically, thecontact substrate 20 is a silicon substrate although other types ofdielectric substrate, such as glass epoxy, polyimide, ceramic, andalumina substrates are also feasible. The contact pad 36 is connected toa PCB (print circuit board) pad 38 provided on a PCB substrate 62through a conductive bump 56 via a single layer TAB lead 74 ₂.

The TAB lead 74 ₂ has a straight shape as in the examples of FIGS. 12and 13. The contact substrate 20 is mounted on the PCB substrate 62through a support structure 52 ₂ and an elastomer 42. The contactsubstrate 20, the elastomer 42, the support structure 52 ₂, and the PCBsubstrate 62 are attached with one another by, for example, applying anadhesive (not shown). In FIG. 14, between the TAB lead 74 ₂ and thesupport structure 52 ₂, there is provided a support member 54 to supportthe TAB lead 74 ₂ extending between the contact pad 36 and the PCB pad38.

By the application of the heat, the conductive bump 56 is reflowed ontothe PCB pad 38 for attachment between the TAB lead 74 ₂ and the PCB pad38. An example of the conductive bump 56 is a solder bump used in astandard solder ball technology. Another example of the conductive bump56 is a fluxless solder ball used in a plasma-assisted dry solderingtechnology.

Further examples of the conductive bump 56 are a conductive polymer bumpand a compliant bump which involve the use of polymer in the bump. Thishelps in minimizing planarization problems or CTE (coefficient oftemperature expansion) mismatches in the packaging and interconnection.There is no reflowing of metal, which prevents bridging between contactpoints. The conductive polymer bump is made of a screen printableconductive adhesive. The compliant bump is a polymer core bump with ametal coating. The polymer is typically plated with gold and iselastically compressible. Still further example of the conductive bump56 is a bump used in a controlled collapse chip connection technology inwhich solder balls are formed by an evaporation process.

The PCB substrate 62 itself may be a probe card such as shown in FIG. 3or provided separately from the probe card and mounted directly orindirectly on the probe card. In the former case, the PCB substrate 62may make direct contact with an interface of a semiconductor test systemsuch as an IC tester in the manner shown in FIG. 2. In the latter case,the PCB substrate 62 is pinned or in use of a conductive polymer forestablishing an electrical contact to the next level. Such types ofelectrical connection between the PCB substrate 62 and the probe cardthrough pins or conductive polymer would allow for field repairability.

The PCB substrate 62 may be a multiple layer structure which is capableof providing high bandwidth signals, distributed high frequencycapacitance and integrated high frequency chip capacitors for powersupply decoupling as well as high pin counts (number of I/O pins andassociated signal paths). An example of material of the PCB substrate 62is standard high performance glass epoxy resin. Another example of thematerial is ceramic which is expected to minimize mismatch incoefficient of temperature expansion (CTE) rates during high temperatureapplication such as a burn-in test of semiconductor wafers and packagedIC devices.

The support structure 52 ₂ is to establish a physical strength of thepackaging and interconnection of the contact structure. The supportstructure 52 ₂ is made of, for example, ceramic, molded plastic ormetal. The elastomer 42 is to establish flexibility in the packaging andinterconnection of the present invention to overcome a potentialplanarization mechanism. The elastomer 42 also functions to absorb amismatch in temperature expansion rates between the contact substrate 20and the PCB substrate 62.

An example of overall length of the signal path extending from thecontact structure 30, the contact trace 32, the contact pad 36 and theTAB lead 74 ₂ is in the range of several hundred micrometers. Because ofthe short path length, the interconnection and packaging of the presentinvention can be easily operable in a high frequency band such asseveral GHz or even higher. Moreover, because of the lower total numberof components to be assembled, the packaging and interconnection of thepresent invention can be fabricated with low cost and high reliabilityas well as high productivity.

FIG. 15 shows a further example of the third embodiment of the presentinvention wherein the bottom type contact pad is coupled to aninterconnect pad provided on a printed circuit board through aconductive polymer. In the example of FIG. 15, a contact structure 30, acontact trace 32, a via hole 35, and a contact pad 36 are formed on acontact substrate 20. The contact structure 30 is formed on the uppersurface of the contact substrate 20 while the contact pad 36 is formedon the bottom surface of the substrate 20. The contact pad 36 isconnected to a PCB (print circuit board) pad 38 provided on a PCBsubstrate 62 through a TAB lead 74 ₂ and a conductive polymer 66.Typically, the contact substrate 20 is a silicon substrate althoughother types of dielectric substrate, such as glass epoxy, polyimide,ceramic, and alumina substrates are also feasible.

In this example, the TAB lead 74 ₂ has a straight shape similar to theexamples of FIGS. 12-14. The contact substrate 20 is mounted on the PCBsubstrate 62 through a support structure 52 ₂ and an elastomer 42. Thecontact substrate 20, the elastomer 42, the support structure 52 ₂, andthe PCB substrate 62 are attached with one another by, for example, anadhesive (not shown)

Most conductive polymers are designed to be conductive between themating electrodes normally in vertical of angled directions and notconductive in the horizontal direction. An example of the conductivepolymer 66 is a conductive elastomer which is filled with conductivewire that extends beyond the surface of the elastomer.

Various other examples of the conductive polymer 66 are possible such asan anisotropic conductive adhesive, anisotropic conductive film,anisotropic conductive paste, and anisotropic conductive particles. Theanisotropic conductive adhesive is filled with conductive particles thatdo not touch each other. The conductive path is formed by pressing theadhesive between the two electrodes at a specific location. Theanisotropic conductive film is a thin dielectric resin filled withconductive particles that do not touch each other. The conductive pathis formed by pressing the film between the two electrodes at a specificlocation.

The anisotropic conductive paste is a screen printable paste which isfilled with conductive particles that do not touch each other. Theconductive path is formed by pressing the paste between the twoelectrodes at a specific location. The anisotropic conductive particleis a thin dielectric resin filled with conductive particles coated witha very thin layer of dielectric material to improve isolation. Theconductive path is formed by pressing the particle with enough force toexplode the dielectric coating on the particles, between the twoelectrodes at a specific location.

The PCB substrate 62 itself may be a probe card such as shown in FIG. 3or provided separately from the probe card and mounted directly orindirectly on the probe card. In the former case, the PCB substrate 62may make direct contact with an interface of a semiconductor test systemsuch as an IC tester in the manner shown in FIG. 2. In the latter case,the PCB substrate 62 is pinned or in use of a conductive polymer forestablishing an electrical contact to the next level. Such types ofelectrical connection between the PCB substrate 62 and the probe cardthrough pins or conductive polymer would allow for field repairability.

The PCB substrate 62 may be a multiple layer structure which is capableof providing high bandwidth signals, distributed high frequencycapacitance and integrated high frequency chip capacitors for powersupply decoupling as well as high pin counts (number of I/O pins andassociated signal paths). An example of material of the PCB substrate 62is standard high performance glass epoxy resin. Another example ofmaterial is ceramic which is expected to minimize mismatch incoefficient of temperature expansion (CTE) rates during high temperatureapplication such as a burn-in test of semiconductor wafers and packagedIC devices.

The support structure 52 ₂ is to establish a physical strength of thepackaging and interconnection of the contact structure. The supportstructure 52 ₂ is made of, for example, ceramic, molded plastic ormetal. The elastomer 42 is to establish flexibility in the packaging andinterconnection of the present invention to overcome a potentialplanarization mechanism. The elastomer 42 also functions to absorb amismatch in temperature expansion rates between the contact substrate 20and the PCB substrate 62.

An example of signal path length involved in this packaging andinterconnection is in the range of several hundred micrometers. Becauseof the short path length, the packaging and interconnection of thepresent invention can be easily operable in a high frequency band suchas several GHz or even higher. Moreover, because of the lower totalnumber of components to be assembled, the interconnection and packagingof the present invention can be fabricated with low cost and highreliability as well as high productivity.

FIGS. 16-23 show a fourth embodiment of the present invention whereinthe bottom type contact pad is coupled to a contact target through adouble layer lead formed by a tape automated bonding (TAB) process. Inthe first example of FIG. 16, a contact structure 30 formed on a contactsubstrate 20 is electrically connected to a contact pad 36 via a contacttrace 32 and a through hole 35. The contact structure 30 is formed onthe upper surface of the contact substrate 20 while the contact pad 36is formed on the bottom surface of the substrate 20. The contact pad 36is connected at its bottom surface with a double layer TAB lead 76 whoseother end is also connected to a printed circuit board (PCB)interconnect pad 38 provided on a PCB substrate 62.

The contact substrate 20 is mounted on the PCB substrate 62 through anelastomer 42 and a support structure 52 ₃. The contact substrate 20, theelastomer 42, the support structure 52 ₃ and the PCB substrate 62 arefixed with one another by, for example, an adhesive (not shown). In thisexample, the double layered TAB lead 76 for connecting the contact pad36 and the PCB pad 38 has an upper lead A and a lower lead B. A supportmember 54 ₂ is provided between the upper lead and the lower lead of theTAB lead 76.

The TAB lead 76 has a gull-wing shape which is similar to the standard“gull-wing lead” lead used in a surface mount technology. Because of thedown-ward bent of the gull-wing type TAB lead 76, a sufficient verticalclearance is achieved at the left side of FIG. 16 over the contactportion between the PCB pad 38 and the TAB lead 76. The lead form of theTAB lead 76 (downward bent, gull-wing lead) may require special toolingto produce the same. Since a large number of interconnection between thecontact pads and the PCB pads will be used in an actual application suchas semiconductor device testing, several hundred connections forexample, such tooling may be standardized for a multiple of contacttraces with given pitch.

The structure of the TAB lead 76 having the tiered leads A and Bestablish a low resistance in a signal path because of two leads runningin parallel. This is useful in transmitting a large current such as in aground line or a power line of a probe card for testing a semiconductordevice with high speed without deforming the waveforms of test signals.

The electrical connections between the contact pad 36 and the TAB lead76 and between the TAB lead 76 and the PCB pad 38 will be established byvarious bonding technologies including thermosonic bonding,thermocompression bonding, and ultrasonic bonding technique. In anotheraspect, such electrical connections will be established through asurface mount technology (SMT) such as using a screen printable solderpaste. A soldering process is carried out based on the reflowcharacteristics of the solder paste and other solder materials wellknown in the art.

The PCB substrate 62 itself may be a probe card such as shown in FIG. 3or provided separately and mounted directly or indirectly on the probecard. In the former case, the PCB substrate 62 may make direct contactwith an interface of a semiconductor test system such as an IC tester ina manner shown in FIG. 2. In the latter case, the PCB substrate 62 ispinned or in use of a conductive polymer for establishing an electricalcontact to the next level of a contact mechanism on the probe card. Suchtypes of electrical connection between the PCB substrate 62 and theprobe card through pins or conductive polymer would allow for fieldrepairability.

The PCB substrate 62 may be a multiple layer structure which is capableof providing high bandwidth signals, distributed high frequencycapacitance and integrated high frequency chip capacitors for powersupply decoupling as well as high pin counts (number of I/O pins andassociated signal paths). An example of material of the PCB 62 isstandard high performance glass epoxy resin. Another example of materialis ceramic which is expected to minimize mismatch in coefficient oftemperature expansion (CTE) rates during high temperature applicationsuch as a burn-in test of semiconductor wafers and packaged IC devices.

The support structure 52 ₃ is to establish a physical strength of thepackaging and interconnection of the contact structure. The supportstructure 52 ₃ is made of, for example, ceramic, molded plastic ormetal. The elastomer 42 is to establish flexibility in the packaging andinterconnection of the present invention to overcome a potentialplanarization mechanism. The elastomer 42 also functions to absorb amismatch in temperature expansion rates between the contact substrate 20and the PCB substrate 62.

An example of overall signal path length extending from the contactstructure 30 to the PCB pad 38 is in the range several hundredmicrometers. Because of the short path length, the packaginginterconnection of the present invention can be easily operable in ahigh frequency band such as several GHz or even higher. Moreover,because of a relatively small number of overall components to beassembled, the packaging and interconnection of the present inventioncan be fabricated with low cost and high reliability as well as highproductivity.

FIG. 17 shows another example of the fourth embodiment of the presentinvention. In this example, a double layered TAB lead 76 ₂ having upperand lower leads A and B is provided to the contact pad 36 connected tothe contact structure 30. The upper lead A is provided in an upper andouter position of FIG. 17 than the lower lead B. The upper lead A isconnected to a PCB pad 38 and the lower lead B is connected to a PCB pad39. To accommodate the PCB pads 38 and 39 thereon, a PCB substrate 62 ₄is arranged to have an edge having a larger thickness, i.e., a step, tomount the PCB pad 38, and an inner portion adjacent to the edge portionhaving a smaller thickness to mount the PCB pad 39.

The electrical connection between the TAB lead 76 ₂ and the PCB pads 38and 39 will be established by a surface mount technology (SMT) such asusing a screen printable solder paste as well as various other bondingtechnologies including thermosonic bonding, thermocompression bonding,and ultrasonic bonding technique. Because of the significantly smallsizes of the components and signal path lengths involved in the contactstructure 30, contact trace 32, contact pad 36, and the TAB lead 76 ₂,the example of FIG. 17 can operate at a very high frequency band, suchas several GHz. Moreover, because of the small number and simplestructure of components to be assembled, the interconnection andpackaging of the present invention can be fabricated with low cost andhigh reliability as well as high productivity.

The structure of the TAB lead 76 ₂ having the double layered leads A andB establishes a fan out in the vertical dimension. This is useful indistributing a signal or power to two or more paths. Another advantageof the fan out is to increase the number of contact pads on both thecontact substrate and the PCB substrate. In other words, it is possibleto decrease the effective pitch (distance) between the contact pads.

FIG. 18 shows a further modification of the fourth embodiment of thepresent invention wherein the bottom type contact pad 36 is coupled to aconnector provided on a printed circuit board or other structure. In theexample of FIG. 18, a contact pad 36 connected to the contact structure30 is connected to a connector 46 ₂ through a double layer TAB lead 76₄. The connector 46 ₂ is provided on a support structure 52 ₅.

Typically, the contact structure 30, contact trace 32, through hole 35and the contact pad 36 are formed on the contact substrate 20 throughphotolithography processes. The contact structure 30 is formed on theupper surface of the contact substrate 20 while the contact pad 36 isformed on the bottom surface of the substrate 20. The contact substrate20 is a silicon substrate although other types of dielectric substrate,such as glass epoxy, polyimide, ceramic, and alumina substrates are alsofeasible.

The connector 46 ₂ may be mechanically fixed to the support structure 52₅ through an attachment mechanism (not shown). The end of the TAB lead76 ₄ is inserted in a receptacle (not shown) of the connector 46 ₂. Asis well known in the art, such a receptacle has a spring mechanism toprovide a sufficient contact force when receiving the end of the TABlead 76 ₄ therein. Between the upper lead A and the lower lead B of thedouble layer TAB lead 76 ₄, there is provided a support member 54 ₂ tosupport the leads A and B of the TAB lead 76 ₄ extending between thecontact pad 36 and the connector 46 ₂. Also well known in the art, aninner surface of such receptacles are provided with conductive metalsuch as gold, silver, palladium or nickel.

The structure of the TAB lead 76 ₄ having the tiered leads A and Bestablish a low resistance in a signal path because of the two leads.This is useful in transmitting a large current such as in a ground lineor a power line for testing a semiconductor device with high speedwithout deforming the waveforms of the test signals.

The connector 46 ₂ may be integrated with straight or right angle pins,which may be connected to the receptacle noted above, for directconnection to a printed circuit board (PCB). A printed circuit board(PCB) to mount the connector 46 ₂ thereon can be either solid orflexible. As is known in the art, a flexible PCB is formed on a flexiblebase material and has flat cables therein. Alternatively, the connector46 ₂ may be integrated with a coaxial cable assembly in which areceptacle is attached to an inner conductor of the coaxial cable forreceiving the ends of the TAB lead 76 ₄ therein. The connection betweenthe connector 46 ₂ and the TAB lead 76 ₄ or the support structure 52 ₅is not a permanent attachment method, allowing for field replacement andrepairability of the contact portion.

The support structure 52 ₅ is to ensure a physical strength of thepackaging and interconnection of the contact structure. The supportstructure 52 ₅ is made of, for example, ceramic, molded plastic ormetal. The elastomer 42 is to establish flexibility in theinterconnection and packaging of the present invention to overcome apotential planarization mechanism. The elastomer 42 also functions toabsorb a mismatch in temperature expansion rates between the contactsubstrate 20 and a PCB substrate to mount the connector 46 ₂ thereon.

FIG. 19 shows a further modification of the fourth embodiment of thepresent invention wherein the bottom type contact pad 36 is coupled to aconnector provided on a printed circuit board or other structure. In theexample of FIG. 19, a contact pad 36 connected to the contact structure30 is connected to a connector 46 ₃ via a double layer TAB lead 76 ₆.The double layer TAB 76 ₆ has an upper lead A and a lower lead B, eachof which is separated from one another at the end. The connector 46 ₃ isprovided on a support structure 52 ₄.

The connector 46 ₃ may be mechanically fixed to the support structure 52₄ through an attachment mechanism (not shown). The ends of the leads Aand B of the TAB lead 76 ₆ are inserted in receptacles (not shown) ofthe connector 46 ₃. As is well known in the art, such a receptacle has aspring mechanism to provide a sufficient contact force when receivingthe end of the TAB lead 76 ₆ therein. Between the upper lead A and thelower lead B of the double layer TAB lead 76 ₆, there is provided asupport member 54 ₄ to support the leads A and B.

The structure of the TAB lead 76 ₆ having the double layered leads A andB establishes a fan out in the vertical dimension. This is useful indistributing a signal or power to two or more paths. Another advantageof the fan out is to increase the number of contact pads, i.e., todecrease the effective pitch (distance) between the contact pads.

FIG. 20 shows a further example of the fourth embodiment of the presentinvention wherein the bottom type contact pad is coupled to aninterconnect pad provided on a printed circuit board through aconductive bump. In the example of FIG. 20, a contact structure 30, acontact trace 32, a through hole 35 and a contact pad 36 are formed on acontact substrate 20. The contact structure 30 is formed on the uppersurface of the contact substrate 20 while the contact pad 36 is formedon the bottom surface of the substrate 20.

Typically, the contact substrate 20 is a silicon substrate althoughother types of dielectric substrate, such as glass epoxy, polyimide,ceramic, and alumina substrates are also feasible. The contact pad 36 atthe bottom of the contact substrate 20 is connected to a PCB (printcircuit board) pad 38 provided on a PCB substrate 62 through aconductive bump 56 through a double layer TAB lead 76 ₄.

The contact substrate 20 is mounted on the PCB substrate 62 through asupport structure 52 ₃ and an elastomer 42. The contact substrate 20,the elastomer 42, the support structure 52 ₃, and the PCB substrate 62are attached with one another by, for example, an adhesive (not shown).Between the upper lead A and the lower lead B of the TAB lead 76 ₄,there is provided with a support member 54 ₂ to support the upper andlower leads A and B.

By the application of the heat, the conductive bump 56 is reflowed ontothe PCB pad 38 for attachment between the TAB lead 76 ₄ and the PCB pad38. An example of the conductive bump 56 is a solder bump used in astandard solder ball technology. Another example of the conductive bump56 is a fluxless solder ball used in a plasma-assisted dry solderingtechnology.

Further examples of the conductive bump 56 are a conductive polymer bumpand a compliant bump which involve the use of polymer in the bump. Thishelps in minimizing planarization problems or CTE (coefficient oftemperature expansion) mismatches in the packaging and interconnection.There is no reflowing of metal, which prevents bridging between contactpoints. The conductive polymer bump is made of a screen printableconductive adhesive. The compliant bump is a polymer core bump with ametal coating. The polymer is typically plated with gold and iselastically compressible. Still further example of the conductive bump56 is a bump used in a controlled collapse chip connection technology inwhich solder balls are formed by an evaporation process.

The structure of the TAB lead 76 ₄ having the tiered leads A and Bestablish a low resistance in a signal path because of the two leads.This is useful in transmitting a large current such as in a ground lineor a power line in a probe card for testing a semiconductor device withhigh speed without deforming the waveforms of the test signals.

FIG. 21 shows a further example of the fourth embodiment of the presentinvention. In this example, a double layered TAB lead 76 ₂ having upperand lower leads A and B are provided to the contact pad 36 connected tothe contact structure 30. The upper lead A is provided in an upper andouter position than the lower lead B in FIG. 21. The upper lead A isconnected to a PCB pad 38 via a conductive dump 56 and the lower lead Bis connected to a PCB pad 39 via a conductive dump 57. To accommodatethe PCB pads 38 and 39 thereon, a PCB substrate 62 ₃ is arranged to havean edge having a larger thickness, i.e., a step, to mount the PCB pad38, and an inner portion adjacent to the edge portion having a smallerthickness to mount the PCB pad 39.

By the application of the heat, the conductive bumps 56 and 57 arereflowed onto the PCB pads 38 and 39 for attachment between the TAB lead76 ₂ and the PCB pads 38 and 39. An example of the conductive bumps 56and 57 is a solder bump used in a standard solder ball technology.Another example of the conductive bumps 56 and 57 is a fluxless solderball used in a plasma-assisted dry soldering technology.

The structure of the TAB lead 76 ₂ having the double layered leads A andB establishes a fan out in the vertical dimension. This is useful indistributing a signal or power to two or more paths. Another advantageof the fan out is to increase the number of contact pads, i.e., todecrease the effective pitch (distance) between the contact pads.

FIG. 22 shows a further example of the fourth embodiment of the presentinvention wherein the bottom type contact pad is coupled to a connectiontarget such as an interconnect pad provided on a printed circuit boardthrough a conductive polymer. In the example of FIG. 22, a contactstructure 30, a contact trace 32, a through hole 35, and a contact pad36 are formed on a contact substrate 20. The contact structure 30 isformed on the upper surface of the contact substrate 20 while thecontact pad 36 is formed on the bottom surface of the substrate 20.Typically, the contact substrate 20 is a silicon substrate althoughother types of dielectric substrate, such as glass epoxy, polyimide,ceramic, and alumina substrates are also feasible. The contact pad 36 isconnected to a PCB (print circuit board) pad 38 provided on a PCBsubstrate 62 through a conductive polymer 66 via a double layer TAB lead76 ₄.

The contact substrate 20 is mounted on the PCB substrate 62 through asupport structure 52 ₃ and an elastomer 42. The contact substrate 20,the elastomer 42, the support structure 52 ₃, and the PCB substrate 62are attached with one another by, for example, an adhesive (not shown).Between the upper lead A and the lower lead B of the TAB lead 76 ₄ thereis provided with a support member 54 ₂ to support the upper and lowerleads A and B.

Most conductive polymers are designed to be conductive between themating electrodes normally in vertical of angled directions and notconductive in the horizontal direction. An example of the conductivepolymer 66 is a conductive elastomer which is filled with conductivewire that extends beyond the surface of the elastomer.

Various other examples of the conductive polymer 66 are possible such asan anisotropic conductive adhesive, anisotropic conductive film,anisotropic conductive paste, and anisotropic conductive particles. Theanisotropic conductive adhesive is filled with conductive particles thatdo not touch each other. The conductive path is formed by pressing theadhesive between the two electrodes at a specific location. Theanisotropic conductive film is a thin dielectric resin filled withconductive particles that do not touch each other. The conductive pathis formed by pressing the film between the two electrodes at a specificlocation.

The anisotropic conductive paste is a screen printable paste which isfilled with conductive particles that do not touch each other. Theconductive path is formed by pressing the paste between the twoelectrodes at a specific location. The anisotropic conductive particleis a thin dielectric resin filled with conductive particles coated witha very thin layer of dielectric material to improve isolation. Theconductive path is formed by pressing the particle with enough force toexplode the dielectric coating on the particles, between the twoelectrodes at a specific location.

The structure of the TAB lead 76 ₄ having the tiered leads A and Bestablish a low resistance in a signal path because of the two leads.This is useful in transmitting a large current such as in a ground lineor a power line in a probe card for testing a semiconductor device withhigh speed without deforming the waveforms of the test signals.

FIG. 23 shows another example of the fourth embodiment of the presentinvention. In this example, a double layered TAB lead 76 ₂ having upperand lower leads A and B are provided to the contact pad 36 connected tothe contact trace 32 and contact structure 30. The upper lead A isprovided in an upper and outer position than the lower lead B in FIG.23. The upper lead A is connected to a PCB (printed circuit board) pad38 via a conductive polymer 66 and the lower lead B is connected to aPCB pad 39 via a conductive polymer 67. To accommodate the PCB pads 38and 39 thereon, a PCB substrate 62 ₃ is arranged to have an edge havinga larger thickness, i.e., a step, to mount the PCB pad 38, and an innerportion adjacent to the edge portion having a smaller thickness to mountthe PCB pad 39.

The electrical connection between the TAB lead 76 ₂ and the PCB pads 38and 39 will be established by a surface mount technology (SMT) such asusing a screen printable solder paste as well as various other bondingtechnologies including thermosonic bonding, thermocompression bonding,and ultrasonic bonding technique.

The structure of the TAB lead 76 ₂ having the double layered leads A andB establishes a fan out in the vertical dimension. This is useful indistributing a signal or power to two or more paths. Another advantageof the fan out is to increase the number of contact pads, i.e., todecrease the effective pitch (distance) between the contact pads.

FIGS. 24-31 show a fifth embodiment of the present invention wherein thebottom type contact pad is coupled to a contact target through a triplelayer lead formed by a tape automated bonding (TAB) process. In thefirst example of FIG. 24, the contact structure 30 formed on a contactsubstrate 20 is electrically connected to the contact pad 36 via thecontact trace 32 and the through hole 35. The contact structure 30 isformed on the upper surface of the contact substrate 20 while thecontact pad 36 is formed on the bottom surface of the substrate 20. Thecontact pad 36 is connected at its bottom surface with a three layer TABlead 78 which is also connected to a printed circuit board (PCB)interconnect pad 38 provided on a PCB substrate 62.

The contact substrate 20 is mounted on the PCB substrate 62 through anelastomer 42 and a support structure 52 ₃. The contact substrate 20, theelastomer 42, the support structure 52 ₃ and the PCB substrate 62 arefixed with one another by, for example, an adhesive (not shown). In thisexample, the triple layered TAB lead 78 for connecting the contact pad36 and the PCB pad 38 has an upper lead A, an intermediate lead B and alower lead C. A support member 54 ₄ is provided between the upper lead Aand the intermediate lead B of the triple layered TAB lead 78. A supportmember 54 ₅ is provided between the intermediate lead B and the lowerlead C of the triple layered TAB lead 78.

The TAB lead 78 as a whole has a gull-wing shape which is similar to thestandard “gull-wing lead” lead used in a surface mount technology.Because of the down-ward bent of the gull-wing type TAB lead 78, asufficient vertical clearance is achieved at the left end of FIG. 24over the contact portion between the PCB pad 38 and the TAB lead 78. Theform of the TAB lead 78 (downward bent, gull-wing lead) may requirespecial tooling to produce the same. Since a large number ofinterconnection between the contact trace and the PCB pad will be usedin the application such as semiconductor testing, several hundredconnections, such tooling may be standardized for a multiple of contacttraces with given pitch.

The structure of the TAB lead 78 having the tiered leads A, B and Cestablishes a low resistance and a large current capacity in a signalpath because of the three conductive leads running in parallel. This isuseful in transmitting a large current such as in a ground line or apower line in a probe card for testing a semiconductor device with highspeed without deforming the waveforms of test signals.

FIG. 25 shows another example of the fifth embodiment of the presentinvention. In this example, a triple layered TAB lead 782 having upper,intermediate and lower leads A, B and C is provided to the contact pad36 connected to the contact trace 32, through hole 35 and contactstructure 30.

The contact structure 30 is formed on the upper surface of the contactsubstrate 20 while the contact pad 36 is formed on the bottom surface ofthe substrate 20.

The upper lead A is provided in an upper and outer position of FIG. 25than the intermediate lead B. The intermediate lead B is provided in anupper and outer position of FIG. 25 than the lower lead C. The upperlead A is connected to a PCB pad 38, the intermediate lead B isconnected to a PCB pad 39, and the lower lead C is connected to a PCBpad 40. To accommodate the PCB pads 38, 39 and 40 thereon, a PCBsubstrate 62 ₄ is arranged to have steps to mount the PCB pads 38, 39and 40 with different vertical positions. A support member 54 ₆ isprovided between the upper lead A and the intermediate lead B and asupport member 54 ₇ is provided between the intermediate lead B and thelower lead C.

The electrical connection between the TAB lead 78 ₂ and the PCB pads 38,39 and 40 will be established by a surface mount technology (SMT) suchas using a screen printable solder paste as well as various otherbonding technologies including thermosonic bonding, thermocompressionbonding, and ultrasonic bonding technique. Because of the significantlysmall sizes of the components and signal path lengths involved in thecontact structure 30, contact trace 32, and the TAB lead 78 ₂, theexample of FIG. 25 can operate at a very high frequency band, such asseveral GHz. Moreover, because of the small number and simple structureof components to be assembled, the interconnection and packaging of thepresent invention can be fabricated with low cost and high reliabilityas well as high productivity.

The structure of the TAB lead 78 ₂ having the triple layered leads A, Band C establishes a fan out in the vertical dimension of the TAB lead.This is useful in distributing a signal or power to two or more paths.Another advantage of the fan out is to increase the number of contactpads, i.e., to decrease the effective pitch (distance) between thecontact pads.

FIG. 26 shows a further modification of the fifth embodiment of thepresent invention wherein the bottom type contact pad 36 is coupled to aconnector provided on a printed circuit board or other structure. In theexample of FIG. 26, a contact pad 36 connected to the contact structure30 is connected to a connector 46 ₂ via a triple layer TAB lead 78 whichhas the same shape as that shown in FIG. 24. The connector 46 ₂ isprovided on a support structure 52 ₄.

The connector 46 ₂ may be mechanically fixed to the support structure 52₄ through an attachment mechanism (not shown). The end of the TAB lead78 is inserted in a receptacle (not shown) of the connector 46 ₂. As iswell known in the art, such a receptacle has a spring mechanism toprovide a sufficient contact force when receiving the end of the TABlead 78 therein. Between the upper lead A and the intermediate lead B ofthe double layer TAB lead 78, there is provided a support member 54 ₄ tosupport the leads A and B. Between the intermediate lead B and the lowerlead C of the double layer TAB lead 78, there is provided a supportmember 54 ₅ to support the leads B and C.

The structure of the TAB lead 78 having the tiered leads A, B and Cestablishes a low resistance and a large current capacity in a signalpath because of the three conductive leads in parallel. This is usefulin transmitting a large current such as in a ground line or a power lineof a probe card for testing a semiconductor device with high speedwithout deforming the waveforms of test signals.

FIG. 27 shows a further modification of the fifth embodiment of thepresent invention wherein the bottom type contact pad 36 is coupled to aconnection target such as a connector provided on a printed circuitboard or other structure. In the example of FIG. 27, a contact pad 36provided at the bottom surface of the contact substrate 20 is connectedto a connector 46 ₄ via a triple layer TAB lead 78 ₂. The triple layerTAB 78 ₂ has an upper lead A, an intermediate lead B and a lower lead Ceach of which is separated at the end. The connector 46 ₄ is provided ona support structure 52 ₄.

The connector 46 ₄ may be mechanically fixed to the support structure 52₄ through an attachment mechanism (not shown). The ends of the leads A,B and C of the TAB lead 78 ₂ are inserted in receptacles (not shown) ofthe connector 46 ₄. As is well known in the art, such a receptacle has aspring mechanism to provide a sufficient contact force when receivingthe end of the TAB lead 78 ₂ therein. A support member 54 ₆ is providedbetween the upper lead A and the intermediate lead B and a supportmember 54 ₇ is provided between the intermediate lead B and the lowerlead C of the triple TAB lead 78 ₂.

The structure of the TAB lead 78 ₂ having the triple layered leads A, Band C establishes a fan out in the vertical dimension of the TAB lead.This is useful in distributing a signal or power to two or more paths.Another advantage of the fan out is to increase the number of contactpads, i.e., to decrease the effective pitch (distance) between thecontact pads.

FIG. 28 shows a further example of the fifth embodiment of the presentinvention wherein the bottom type contact pad is coupled to a connectiontarget such as an interconnect pad provided on a printed circuit boardthrough a conductive bump. In the example of FIG. 28, a contactstructure 30, a contact trace 32, a through hole 35 and a contact pad 36are formed on a contact substrate 20. The contact structure 30 is formedon the upper surface of the contact substrate 20 while the contact pad36 is formed on the bottom surface of the substrate 20. Typically, thecontact substrate 20 is a silicon substrate although other types ofdielectric substrate, such as glass epoxy, polyimide, ceramic, andalumina substrates are also feasible. The contact pad 36 is connected toa PCB (print circuit board) pad 38 provided on a PCB substrate 62through a conductive bump 56 via a triple layer TAB lead 78.

The contact substrate 20 is mounted on the PCB substrate 62 through asupport structure 52 ₃ and an elastomer 42. The contact substrate 20,the elastomer 42, the support structure 52 ₃, and the PCB substrate 62are attached with one another by, for example, applying an adhesive (notshown). Between the upper lead A and the intermediate lead B of thetriple layer TAB lead 78, there is provided a support member 54 ₄ tosupport the leads A and B. Between the intermediate lead B and the lowerlead C of the triple layer TAB lead 78, there is provided a supportmember 54 ₅ to support the leads B and C.

The structure of the TAB lead 78 having the tiered leads A, B and Cestablishes a low resistance and a large current capacity in a signalpath because of the three conductive leads running in parallel. This isuseful in transmitting a large current such as in a ground line or apower line in a probe card for testing a semiconductor device with highspeed without deforming the waveforms of test signals.

By the application of the heat, the conductive bump 56 is reflowed ontothe PCB pad 38 for attachment between the TAB lead 78 and the PCB pad38. An example of the conductive bump 56 is a solder bump used in astandard solder ball technology. Another example of the conductive bump56 is a fluxless solder ball used in a plasma-assisted dry solderingtechnology.

FIG. 29 shows another example of the fifth embodiment of the presentinvention. In this example, a triple layered TAB lead 78 ₂ having upper,intermediate and lower leads A, B and C is provided to the contact pad36 connected to the contact structure 30. The upper lead A is providedin an upper and outer position of FIG. 29 than the intermediate lead B.The intermediate lead B is provided in an upper and outer position thanthe lower lead C in FIG. 29. The upper lead A is connected to a PCB pad38 through a conductive bump 56, the intermediate lead B is connected toa PCB pad 39 through a conductive bump 57, and the lower lead C isconnected to a PCB pad 40 through a conductive bump 58. To accommodatethe PCB pads 38, 39 and 40 thereon, a PCB substrate 62 ₄ is arranged tohave steps to mount the PCB pads 38, 39 and 40 with different verticalpositions. A support member 54 ₆ is provided between the upper lead Aand the intermediate lead B and a support member 54 ₇ is providedbetween the intermediate lead B and the lower lead C.

By the application of the heat, the conductive bumps 56, 57 and 58 arereflowed onto the PCB pads 38, 39 and 40 for attachment between the TABlead 78 ₂ and the PCB pads 38, 39 and 40. An example of the conductivebumps 56, 57 and 58 is a solder bump used in a standard solder balltechnology. Another example of the conductive bumps 56, 57 and 58 is afluxless solder ball used in a plasma-assisted dry soldering technology.

The structure of the TAB lead 78 ₂ having the triple layered leads A, Band C establishes a fan out in the vertical dimension of the TAB lead.This is useful in distributing a signal or power to two or more paths.Another advantage of the fan out is to increase the number of contactpads, i.e., to decrease the effective pitch (distance) between thecontact pads.

FIG. 30 shows a further example of the fifth embodiment of the presentinvention wherein the bottom type contact pad is coupled to aninterconnect pad provided on a printed circuit board through aconductive polymer. In the example of FIG. 30, a contact structure 30, acontact trace 32, a through hole and a contact pad 36 are formed on acontact substrate 20. The contact structure 30 is formed on the uppersurface of the contact substrate 20 while the contact pad 36 is formedon the bottom surface of the substrate 20. Typically, the contactsubstrate 20 is a silicon substrate although other types of dielectricsubstrate, such as glass epoxy, polyimide, ceramic, and aluminasubstrates are also feasible. The contact pad 36 is connected to acontact target such as a PCB (printed circuit board) pad 38 provided ona PCB substrate 62 through a conductive polymer 66 via a triple layerTAB lead 78.

The contact substrate 20 is mounted on the PCB substrate 62 through asupport structure 52 ₃ and an elastomer 42. The contact substrate 20,the elastomer 42, the support structure 52 ₃, and the PCB substrate 62are attached with one another by, for example, an adhesive (not shown).Between the upper lead A and the intermediate lead B of the double layerTAB lead 78, there is provided a support member 54 ₄ to support theleads A and B. Between the intermediate lead B and the lower lead C ofthe double layer TAB lead 78, there is provided a support member 54 ₅ tosupport the leads B and C.

Most conductive polymers are designed to be conductive between themating electrodes normally in vertical of angled directions and notconductive in the horizontal direction. An example of the conductivepolymer 66 is a conductive elastomer which is filled with conductivewire that extends beyond the surface of the elastomer.

Various other examples of the conductive polymer 66 are possible such asan anisotropic conductive adhesive, anisotropic conductive film,anisotropic conductive paste, and anisotropic conductive particles. Theanisotropic conductive adhesive is filled with conductive particles thatdo not touch each other. The conductive path is formed by pressing theadhesive between the two electrodes at a specific location. Theanisotropic conductive film is a thin dielectric resin filled withconductive particles that do not touch each other. The conductive pathis formed by pressing the film between the two electrodes at a specificlocation.

The anisotropic conductive paste is a screen printable paste which isfilled with conductive particles that do not touch each other. Theconductive path is formed by pressing the paste between the twoelectrodes at a specific location. The anisotropic conductive particleis a thin dielectric resin filled with conductive particles coated witha very thin layer of dielectric material to improve isolation. Theconductive path is formed by pressing the particle with enough force toexplode the dielectric coating on the particles, between the twoelectrodes at a specific location.

The structure of the TAB lead 78 having the tiered leads A, B and Cestablish a low resistance and a large current capacity in a signal pathbecause of the three conductive leads. This is useful in transmitting alarge current such as in a ground line or a power line for testing asemiconductor device with high speed without deforming the waveforms oftest signals.

FIG. 31 shows another example of the fifth embodiment of the presentinvention. In this example, a triple layered TAB lead 78 ₂ having upper,intermediate and lower leads A, B and C is provided to the contact pad36 connected to the contact trace 32 and contact structure 30. The upperlead A is provided in an upper and outer position than the intermediatelead B in FIG. 31. The intermediate lead B is provided in an upper andouter position of FIG. 31 than the lower lead C. The upper lead A isconnected to a PCB pad 38 through a conductive polymer 66, theintermediate lead B is connected to a PCB pad 39 through a conductivepolymer 67, and the lower lead C is connected to a PCB pad 40 through aconductive polymer 68. To accommodate the PCB pads 38, 39 and 40thereon, a PCB substrate 62 ₄ is arranged to have steps to mount the PCBpads 38, 39 and 40 with different vertical positions. A support member54 ₆ is provided between the upper lead A and the intermediate lead Band a support member 54 ₇ is provided between the intermediate lead Band the lower lead C.

The structure of the TAB lead 78 ₂ having the triple layered leads A, Band C establishes a fan out in the vertical dimension of the TAB lead.This is useful in distributing a signal or power to two or more paths.Another advantage of the fan out is to increase the number of contactpads, i.e., to decrease the effective pitch (distance) between thecontact pads.

FIG. 32 shows a sixth embodiment of the present invention wherein a topcontact trace is coupled to a first contact target through a singlelayer TAB lead while a bottom type contact pad is coupled to a secondcontact target through a double layer TAB lead. In the example of FIG.32, the contact structure 30 formed on a contact substrate 20 iselectrically connected to the contact pad 36 via the contact trace 32and the through hole 35. The contact structure 30 and the contact trace32 are formed on the upper surface of the contact substrate 20 while thecontact pad 36 is formed on the bottom surface of the substrate 20.

The contact trace 32 is connected at its upper surface to a single layerTAB lead 79 whose other end is connected to a printed circuit board(PCB) pad 38 on a PCB substrate 623 through a conductive polymer 66. Thecontact pad 36 is connected at its bottom surface with a two layer TABlead 76 ₄ whose other end is connected to a PCB pad 39 on the PCBsubstrate 62 ₃ through a conductive polymer 67.

The contact substrate 20 is mounted on the PCB substrate 62 ₃ through anelastomer 42 and a support structure 52 ₃. The contact substrate 20, theelastomer 42, the support structure 52 ₃ and the PCB substrate 62 arefixed with one another by, for example, an adhesive (not shown). In thisexample, the single layer TAB lead 79 for connecting the contact trace32 and the contact pad 38 is supported by a support member 54 ₈ which isprovided between the TAB leads 79 and 76 ₄. The double layered TAB lead76 ₄ for connecting the contact pad 36 and the PCB pad 39 has an upperlead A and a lower lead B. A support member 54 ₂ is provided between theupper lead A and the lower lead B of the double layered TAB lead 76 ₄.In this embodiment, the conductive polymer 66 and 67 can be replacedwith conductive bumps such as solder balls for connecting the contactstructure to the PCB pads 38 and 39. Alternatively, the TAB leads 79 and76 ₄ can be directly connected to the PCB pads 38 and 39.

The structure of the TAB lead 79 having the single lead and the TAB lead76 ₄ having the tiered leads A and B establishes a low resistance and alarge current capacity in a signal path because of the three conductiveleads running in parallel. This is useful in transmitting a largecurrent such as in a ground line or a power line in a probe card fortesting a semiconductor device with high speed without deforming thewaveforms of test signals. The structure of TAB leads in FIG. 32 alsoachieves flexibility in increasing the number of contact pads.

According to the present invention, the packaging and interconnectionhas a very high frequency bandwidth to meet the test requirements in thenext generation semiconductor technology. The packaging andinterconnection is able to mount the contact structure on a probe cardor equivalent thereof by electrically connecting therewith from thebottom of the contact substrate mounting the contact structure.Moreover, because of a relatively small number of overall components tobe assembled, the interconnection and packaging of the present inventioncan be fabricated with low cost and high reliability as well as highproductivity.

Although only a preferred embodiment is specifically illustrated anddescribed herein, it will be appreciated that many modifications andvariations of the present invention are possible in light of the aboveteachings and within the purview of the appended claims withoutdeparting the spirit and intended scope of the invention.

What is claimed is:
 1. A packaging and interconnection of a contactstructure, comprising: a contact structure made of conductive materialand formed on a contact substrate, said contact structure having a baseportion vertically formed on the contact substrate, a horizontal portionone end of which is formed on said base portion, and a contact portionvertically formed on another end of said horizontal portion; a contacttrace formed on an upper surface of the contact substrate andelectrically connected to the contact structure at one end andhorizontally extended on the upper surface to be substantially remotefrom the contact structure at other end; a contact pad formed on abottom surface of the contact substrate substantially horizontallyremote from the contact structure and electrically connected to thecontact structure through a via hole and said other end of the contacttrace; a connection target provided at an outer periphery of the contactstructure in a side-by-side fashion with the contact structure to beelectrically connected with the contact pad on the contact substrate;and a double layer lead having at least a portion where a conductivelead thereof is separated into two for electrically connecting thecontact pad provided at the bottom surface of the contact substrate andthe connection target.
 2. A packaging and interconnection of a contactstructure as defined in claim 1, further comprising: an elastomerprovided under said contact substrate for allowing flexibility in saidinterconnection and packaging; and a support structure provided betweensaid elastomer and said connection target for supporting said contactstructure, said contact substrate and said elastomer.
 3. A packaging andinterconnection of a contact structure as defined in claim 1, whereinsaid connection target is a multilayer printed circuit board (PCB)substrate made of glass epoxy resin or ceramic.
 4. A packaging andinterconnection of a contact structure as defined in claim 2, whereinsaid support structure is made of ceramic, molded plastic or metal.
 5. Apackaging and interconnection of a contact structure as defined in claim1, wherein said double layer lead is formed in a tape automated bonding(TAB) structure.
 6. A packaging and interconnection of a contactstructure as defined in claim 1, wherein one end of said double layerlead is connected to said connection target through a conductive bump.7. A packaging and interconnection of a contact structure as defined inclaim 6, wherein said conductive bump is a solder ball which reflowswhen heat is applied thereto to electrically connect said other end ofsaid double layer lead and said connection target.
 8. A packaging andinterconnection of a contact structure as defined in claim 6, whereinsaid conductive bump is a conductive polymer bump or a compliant bump toelectrically connect said other end of said double layer lead and saidconnection target.
 9. A packaging and interconnection of a contactstructure as defined in claim 1, wherein one end of said double layerlead is connected to said connection target through a conductivepolymer.
 10. A packaging and interconnection of a contact structure asdefined in claim 9, wherein said conductive polymer is made of aconductive adhesive, a conductive film, conductive paste or conductiveparticles.
 11. A packaging and interconnection of a contact structure asdefined in claim 9, wherein said conductive polymer is a conductiveelastomer including an anisotropic conductive adhesive, anisotropicconductive film, anisotropic conductive paste or anisotropic conductiveparticles to electrically connect said end of said double layer lead tosaid connection target.
 12. A packaging and interconnection of a contactstructure as defined in claim 1, wherein one end of said double layerlead is formed of an upper lead and a lower lead to be respectivelyconnected to corresponding connection pads provided on said connectiontarget.
 13. A packaging and interconnection of a contact structure asdefined in claim 12, wherein said upper lead and said lower lead arerespectively connected to said corresponding connection pads provided onsaid connection target through corresponding conductive bumps.
 14. Apackaging and interconnection of a contact structure as defined in claim12, wherein said upper lead and said lower lead are respectivelyconnected to said corresponding connection pads provided on saidconnection target through corresponding conductive polymers.